The invention relates to a coupling unit for coupling two tubular membrane elements of a kind applied in membrane filter technology, which membrane elements form extensions of one another.
As is probably known, membrane filtration is a separation technique in which liquids and gasses are separated with the aid of membrane elements. Some of the substances are retained and the rest of the substances pass through the membrane. Thus, a feed stream to be purified is divided into a purified production stream and a concentrate stream.
In a known membrane filter technique a plurality of membrane elements is connected in series and placed into a tubular pressure vessel. The pressure vessel fits closely around the membrane elements, with sealing rings provided between the membrane elements and the pressure vessel. The membrane elements and the pressure vessel thus form an assembled unit.